I may not understand all the details of what I'm asking but trying to wrap my head around it.
I am aware that before WAAS, some GPS aircraft were equipped to get vertical guidance by a Barocorrected altitude information sent to the FMS and along with the non-waas GPS could calculate (interpolate) glide path info and were approved to fly LNAV/VNAV approaches.
My question is whether the non-waas Garmin 530 has the ability and necessary FAA approval to perform this and if it is an option?